While Black Friday is known for its doorbuster deals, the shopping holiday has grown so big it has seeped into Thursday.

What most people call Thanksgiving is now being called Gray Thursday thanks to big-box stores that are opening early to maximize profits over the holiday weekend. Walmart, Target and Kmart are among the dozens of stores that are opening on Thanksgiving – some as early as 6 a.m. – to offer continuous shopping through the four-day weekend.

“From a retailer’s point of view, if a competitor does it, you feel compelled to do it, too,” Chris Christopher, a retail economist with HIS Global Insight, told the Tampa (Fla.) Tribune. “Another thing is, e-commerce companies are always open, so retailers feel the competition.”

While most major retailers used to open their doors to seething mobs of customers at 12:01 a.m. on Black Friday, this year many are opening on Thanksgiving night and morning. Kmart opens at 6 a.m., Toys-R-Us at 5 p.m., BestBuy at 6 p.m. and Macy’s, Sears, JCPenney, Target and Kohl’s at 8 p.m.

While Kmart has usually kept its stores open on Thanksgiving Day, Target extended its hours to stay competitive. “Last year Target stores opened 9 p.m. on Thanksgiving Day. This year we elected to open one hour earlier to remain competitive and meet the needs of our guests,” Jessica Barrutia, a spokeswoman for the firm with HKStrategies, said.

While “Gray Thursday” may take away from turkey time, some shoppers can’t resist a good deal. “I think it’s ridiculous, but we’re still going to do it,” Austen Carpenter, a long-time Black Friday super-shopper, told CBS Denver.

And it’s this consumer mindset that launched Gray Thursday in the first place, analysts say.

"Despite some claims last year that retailers would ruin the holiday by choosing to be open for business, consumers showed that given the opportunity, they are more than happy to make shopping a part of their Thanksgiving Day activities," said Rick McAllister, president of the Florida Retail Federation. "It is a decision ultimately driven by customer demand, and it looks like Turkey Day shopping is here to stay."

Longer store hours also means less family time for store workers.

"We understand many associates want to spend time with their families during the holiday," Kmart said in a statement. "With this in mind Kmart stores do their very best to staff with seasonal associates and those who are needed to work holidays. All associates who work on Thanksgiving are compensated with holiday pay.”

Jane Matteson, a sales associate at JCPenny’s, says the new hours come with the territory of working in retail.

"I've been in retail for 40 years, and that's just the way it is," Matteson told the Sarasota (Fla.) Herald-Tribune. "I'll still have turkey and watch football and everything, and then I'll come to work. If you don't like it, get out of retail."

Karlene Liscum, a zone manager for Walmart, has decided to get the best of both worlds. She scheduled an early Thanksgiving dinner with her family to work around her 2 p.m. to 11 p.m. shift.

"We'll probably have dinner around noon," she said. "And I don't have to do any of the cooking, so I get to reap the rewards."